1. Institute of Physics of Condensed Matter (IPMC), Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
2. Unit of Anatomy, Department of Medicine, University of Fribourg, Route Albert-Gockel 1, CH-1700 Fribourg, Switzerland
3. Laboratoire Cytopath, Avenue Cardinal-Mermillod 36, 1227 Carouge, Switzerland